Thank you for that Judy. I didn't know that. A recent contact of mine gave me the following information, which he said came from notes he made at a time when he did have access to the census. So it's puzzling to know where he got the non head of household information.

“John Cavendish shows up in the 1840 census as a blacksmith in Ohio, from IOM. Also from IOM is an Eleanor Kissick, 20, seamstress, with a newborn child, John Cavendish.

“In 1860, she was Ellen 38; John Cavendish was a clerk of 20 and also in their household was an Isabel Kissock 62 from IOM.”

I was hoping to find even a small bit more information on any of these three people. I believe the elder John Cavendish survived until May 1870, and Ellen Kissick with younger John Cavendish are apparently in the 1870 census in Ohio.